The responsible use of material resources is an important aspect of sustainable development. It can be promoted using different strategies:
- reuse and recycling
- use of renewable resources
- responsible primary material production
- efficient use of resources.
Whereas the first two can be used to classify different materials, strategies 3 and 4 have to be applied to all types of material to enable sustainable development. The metal industry proposed the material classification of Permanent Materials (PeM) with the aim of emphasizing the possible benefits of the strategy of repeated “reuse and recycling”. The goal of this study was to find a scientific based definition for this new material category in the context of sustainable development – the Concept of Permanent Materials (CPeM). This definition needed not only to address the material properties but also the different aspects of sustainable development and had to resonate with policy makers and the public at large as well as different experts.
As a result of this study, the Concept of Permanent Materials (CPeM) specifically designated those materials which have both permanent properties and respect a material stewardship consisting of material availability, legal compliance and enhanced sustainable development. Materials can only be classified as in full compliance with the CPeM if the requirements of both level – physical-chemical properties and material stewardship – are fulfilled.
The CPeM was discussed with experts and tested on selected material. The classification of materials into permanent and non-permanent categories was found to be credible. Next steps are the integration into sustainable development assessment tools and the communication of the CPeM whilst taking into account that there is an optimal material, permanent or not, for each application.